Key for small film cameras



June 2, 1970 0. BECKER ETAL 3,515,044

KEY FOR- SMALL FILM CAMERAS Filed Feb. 19, 1968 2 Sheets$heet 1' June 2,1970 D. BECKER ETAL 3,515,044

KEY FOR SMALL FILM CAMERAS Filed Feb. 19, 1968 2 Sheets-Sheet 2 United States Patent Oifice 3,515,044 Patented June 2, 1970 Int. Cl. c631 7/00 US. Cl. 95-1 2 Claims ABSTRACT OF THE DISCLOSURE A key for use with a photographic camera provided with a socket for the insertion of a lamp which when inserted operates a filter actuating mechanism for moving a conversion filter out of alignment with the optical axis of the camera. The key is to be used when no lamp is to be inserted into the socket. The key comprises a single rectangular plate which is adapted to operate the filter actuating mechanism and has at one end a loop-shaped handle which projects from the socket of the camera when the other end of the plate has been inserted in the socket and has operated the filter actuating mechanism. The plate is of such a small thickness that the handle may be used as a tool for turning screws provided with a coin slot which may be engaged by the handle.

The invention relates to a key for manipulating a conversion filter arranged in the exposure light beam path of a small film camera.

Keys of this type are used in cameras loaded with an artificial light film for making daylight and artificial light exposures. For daylight exposures, a conversion filter is placed in the exposure light beam of such cameras for the purpose of approximating the color temperature of daylight by filtering to that of artificial light. In this manner color deviations among exposures for which daylight or artificial light is alternately available can be avoided.

For removing the conversion filter from the exposure light beam path, the above mentioned cameras are provided with a lamp holder or socket and a control device for the filter which cooperates with the base of the lamp. When the lamp base is inserted into the lamp holder or socket of the camera, the mentioned control device pivotally moves the conversion fi'lter out of the exposure light beam path.

If now artificial light exposures are to be made with lamps which are not attached to the camera, the filter is no longer automatically removed by the lamp base. Here is where the invention comes in.

The object of the invention is a key for controlling the displacement of a conversion filter arranged in the exposure light beam path of a small film camera. In accordance with the invention, the key is so constructed as to be as versatile as possible. As a separate and relatively small item it should be guarded against loss, yet readily available for use. Cost and material expended on it should remain within appropriate bounds.

According to the invention, the key on one hand has the shape of a lamp base used for controlling the displacement of said conversion filter, and on the other hand is constructed as a tool or a screw driver for tightening and loosening coin slot screws and has a loop or' ring with a slot therein serving as a handle.

This key is used for controlling the displacement of a conversion filter and for tightening and loosening coin slot screws of which there is at least one provided on the camera, for instance on the closure flap for the battery compartment.

The loop on the key constitutes a handle for pulling the key out of the lamp socket of the camera.

The loop in further developing the inventive concept is provided with a slot so that the key, when not in use, may be hooked to an attachment ring or the like provided on a camera carrying strap for the purpose of preventing its loss or misplacement.

Arranging the slot in the loop according to the invention on the side will not impair the function of the key as a tool for attaching or detaching of coin slot screws.

In the following the invention will be further described with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation view of the key according to the invention;

FIG. 2 is a top view of the key;

FIG. 3 is a front elevation View of a small film camera, partly in section, having a key in accordance with the invention partly inserted into its lamp holder, while another key is attached to a metal loop provided on the carrying strap of the camera, and

FIG. 4 is a view similar to FIG. 3, but with the key of the invention completely in its operative position.

Referring to FIG. 1, the body 1 of the key is formed by a plate which is provided with a rectangular aperture 3 at its end :portion 2 which serves for controlling the displacement of the conversion filter. At its other end, the body 1 of the key is provided with a circular loop 4 which on one side is provided with a slot 5.

The thickness of the plate forming the body 1 of the key is relatively small as shown in FIG. 2. This small thickness and the circular shape of the loop 4 give the key the form of a coin which is usually used for tightening or loosening so called coin slot screws.

For the purpose of indicating its use, the body 1 of the key is marked on both sides with a lamp symbol 6.

For pivotally moving the conversion filter 7 out of the exposure light beam path whose center axis is coincident with the optical axis 9 of the camera 8, the key is inserted with its end portion 2 into the lamp holder or socket 10 of the camera 8. The other loop-shaped end 4 of the key will project from the upper wall of the camera 8 and forms a handle for removing the key after an artificial light exposure has been made, and after such a removal of the key the conversion filter 7 will return to its position within the exposure light beam path.

In order to loosen or tighten a coin-slot screw which, for instance, is provided on the cover plate for a battery compartment, the loop 4 on the body 1 of the key is inserted into the coin slot.

When the key is no longer used, it is hooked with its slot -5 to a metal loop .11 or the like, provided on the carrying strap 12 of the camera.

The operation of the key when inserted in place of a lamp base into the lamp holder of the camera is as follows:

The lamp holder 10 is arranged in the camera 8 with its socket 10' in alignment with a slot 13 provided in the camera wall 8'. A small ball 15 is inserted into a lateral hole 14 in the wall of the holder 10 and by means of a U-shaped leaf spring 16 on the holder 10 the ball 15 is urged inwardly toward the socket 10'. A pin 17 extends from the interior of the camera axially into the lower end of the holder 10. The lower end of the pin 17 is attached to a vertically movable slide 18 which is slidably supported by a fixed vertical guide 19 secured within the camera 8. A spring 20 attached with one end to a fixed portion of the camera and with its other end to a bracket 21 on the slide 18 urges the slide 18 constantly upwardly and against an abutment 19' on the guide 19. The bracket 21 is provided with a slot 21', thus forming a fork engaging a pin 22 on anarr'n of a double-armed lever 23 pivotally supported on 23 of the lever 23 is provided with two light transmitting apertures 25, 26 of which one has mounted therein the conversiodfilter 7 'whilelthe other aperture 25 has mounted therein a clear glass plate 27.

'Whenthe .lever 23 is in the position shown in FIG. 3, the conversion filter 7 is positioned in axial alignment with the optical axis 9 of the camera objective. Upon inserting the'key completelyinto the lamp holder socket 10', as shown in FIG.4, the ball will enter the aperture 3 in the-key and lock the latter in this position against the action of the spring 20. The key in this position has pushed the pin '17 and therewith the slide 18 downwardly. As a'further result the forked bracket 21 has moved the pin 22 and therewith the double-armed lever 23 anti-clockwise so that the conversion filter7 is moved transversely away from the optical axis 9, and the clear glass plate 27 is moved into axial alignment with the optical axis 9 of the camera objective.

Upon removal of the key from the lamp holder 10 the spring returns the parts 18, 21, 23 and 7 to the starting position illustrated in'FIG. 3 in which the conversion filter 7 is in axial alignment with the optical axis 9 of the camera objective.

What we claim is:

a 1. A key for use with a photographic camera provided with a socket forming a lamp holder and a movable mounted conversion filter in axial alignment with the optical axis, and filter actuating means extending from said socket to said conversion filter for moving it out of axial "alignment'vv ith s'aidoptical a'xis'whe'n a lamp or salid'key is inserted into said socket, said key comprising a single rectangular plate of a width to permit said plate to be inserted into said socket, said plate when inserted a predetermined distance into said socket causing said filter actuating means to be operated in such a manner that the conversion filter is moved out of axial alignment with said optical axis, the portion'of said plate projecting from said socket in this position having the shape of a loop serving asa handle; said 100p being open at one vertical edge of said plate which merges into said loop, said plate being of such a small thickness that said loop-shaped handle may be used as a tool for turning a screw having a coin slot in one of its ends.

2; A key according to claim 1, in which that portion of the plate coming to lie in the socket of the lamp holder is provided with an aperture for receiving a ball which is yieldably mounted in said socket and locks said plate in a predetermined position in which said filter actuating means has been actuated.

References Cited UNITED STATES PATENTS 3,333,093 7/1967 Robinson -1 NORTON ANSHER, Primary Examiner RICHARD M. SHEER, Assistant Examiner 

